In interfacing optical fibers with one another in splices and connections, it is essential to provide that each of the optical fibers to be coupled, have end surfaces perpendicular to longitudinal axis of the fiber with little or no variation. Further, it is also necessary to provide an end face which is nearly mirror smooth.
In order to obtain this smooth, perpendicular end face, the art has developed various methods of cutting the fiber. One such method involves grinding or polishing the end surface to provide the desired facing, or alternatively to apply chemical solvents to smooth over rough areas. Polishing or chemical reducing is not desirable as it is timeconsuming and costly and as such, cannot be used for field installation. Another such method is to cleave the optical fiber so as to provide this smooth, perpendicular face.
Optical cleaving tools of the type shown and described in U.S. Pat. No. 4,315,368, issued Feb. 16, 1982, and U.S. Pat. No. 4,372,048 issued Feb. 8, 1983, both assigned to the assignee of the present invention, provide for fiber end faces by cleaving the fiber along a longitudinal segment. A fiber scoring blade is brought in contact with a supported extent of optical fiber and scores or nicks the surface of the fiber. About this scored point, the fiber can be separated as by application of tension to ideally leave a smooth, perpendicular end face. One such application of this principal is shown and described in U.S. Pat. No. 4,202,475, issued May 13, 1980 to Harai et al, wherein the fiber is moved toward a scoring blade, then is flexed or bent at the point of the score to effect a sever.
In practice, however, due to the stresses placed upon the fiber by the cleaving blade, the severed end face often has rough, uneven portions which may tend to diminish optical transmission capabilities. Not only does the radial compressive stress transmitted by the cleaving blade cause this imperfection, but also the insertion of the blade itself may inhibit a smooth finish. Overinsertion of the blade may cause a shattering of the fiber end, while underinsertion will not provide enough of a nick to permit a clean sever.
It is desirable to provide an optical fiber cleaving device which can score the fiber so that upon severing, a smooth, perpendicular end face will remain.